Blow-out preventer



April 14, 1936. A. L. RODGERS 2,037,593

BLOW-OUT PREVENTER Filed Sept. 27, 1935 5 Sheets-Sheet 1 INVENTORV BTU-Lu? L- R 1:! 1 1g l ATTORN EY.

5| LUSH 0a Muo BITCH) April 14, 1936. RODGERS 2,037,593

BLOW-OUT PREVENTER Filed Sept. 27, 1935 5 Sheets-Sheet 2 FIG. 4.

INVENTOR.

Aflhur' L-Elilg EPE BY %/4%2 ATTORNEY.

April 14, 1936. A. 1.. RODGERS BLOW- OUT PREVENTER Filed Sept. 27, 1935 5 Sheets-Sheet 3 ArThur Ll? 131:1 EYEFEL ATTORNEY.

Patented A r. 14, 1936 UNITED STATES, PATENT OFFICE 1,037,593 nLow-oo'r rnnvnmit Arthur L. Rodgers, Livingston, Tex. application September 27,1935, Serial No. 42,542

(Claims This invention relates to oil well drilling, and more particularly to blow-out preventers for use in conjunction with oil wells.

Various types of mechanisms for closing oil wells automatically and manually against dangerous pressures have been proposed. The prior used devices for the most part, however, have one or more of the following defects, namely, in-

ability to continue drilling after the slips have been raised to closed position; escape of fluid pressure between the slips and easing wall; and failure to provide movement of the slips from inoperative to operative position in unison and without binding tendency.

This invention has as an object an improved blow-out preventer which eliminates the defects of the prior devices designed for the same purpose. A further object is a blow-out preventer which completely seals the well against the escape of fluid pressure and which at the same time permits continued rotation of the drill pipe. A further object resides in means for insuring swift, simultaneous and facile movement of the blowout preventing parts into operative position. Other objects reside in various details of construction as will be more fully pointed out hereinafter.

In the drawings:

Fig. 1 is a plan view showing the blow-out preventer as it is installed over an-oil well with the associated drilling apparatus;

Fig. 2 is a view in elevation of the blow-out preventer and associated-parts;

Fig. 3 is a sectional view taken on the line 33 of Fig. 4;

Fig. 4 is a vertical sectional view taken through the blow-out preventer;

Fig. 5 is a plan view of one of the slips;

Fig. 6 is a view in elevation looking toward the right edge of the slip shown in Fig. 5;

Fig. 7 is a sectional view taken on the line 'Il of Fig. 4;

Fig. 8 is a plan'view pf the lower member of the blow-out preventer with a part broken away; and

Fig. 9 is a sectional view taken on the lines-9 of Fig. 4.

The upper member I of my improved blow-out preventer is a bowl of conical formation, the converging walls of which are disposed at about a 24 angle. The drill pipe 2 passes through the opening at the top or small end of the bowl and I extends through a lower bowl 3 and through the shaft 6 which terminates at its upper end into an enlarged part I through which mud and water are introduced from the flexible hose 8 leading from the mud pit into the hollow shaft 6 and through the drill pipe 2. The square shaft 6 5 poses through the gear 9 and is made rigid therewith by the usual means to be driven by the gear 9 which is rotated by the pinion I0 connected to a suitable source of power.

The driving mechanism on the floor I I, the hol- 10 low shaft or Kelley joint 6, swivel joint I3, gooseneck I2 connected to hose 8, and-traveling block hook I4, are all associated in the usual manner.

During the drilling operation slush or mud is pumped from the pit I5 into the pipe I6, through 16 the hose 8 and into the drill pipe to the drill operating in the well. The mud then passes up through the annular space H and out, through the opening I8 provided in the tubular extension I9,of the lower member of the blow-out prego venter. The mud then runs into the mud ditch and into the pit.

The tubular extension I! is also provided with a second and smaller opening 20 (Fig. 4). The purpose of this opening is to introduce, through 9.5 line 22 from the pit, mud into the well shaft whenthe drill pipe must be removed for any reason so as to bring the mud level to where it was before removal of the pipe and hence maintain the opposing pressure against that in the so well. To this end the valve 2| is closed and the valve 23 is opened.

The engine and draw works are indicated generally by the numeral 24, the pumps by P and the valves by V. The water supply 25 furnishes, 35 through the pumps, conduits and valves shown, fluid pressure for operating the slips in the blowout preventer in the manner more fully described hereinafter.

- Disposed within the bowl I are a plurality of 40 conical slips 26 the number of which should be at least four. These slips are equal segments of a truncated cone having their edges at the conical axis cut away throughout their length to form the curved surfaces 21 which when the segments 45 are fitted together form a cylindrical closure or conduit. In Fig. 5 the flat top of the slip is indicated at 28 and the sloping sides which constitute the conical surface are indicated at 29, the remaining surface for lightness being cut away to form two recesses or chambers 30.

Each slip is provided with a T-way slot 3| at the center of its conical surface running from the top toward the bottom of the slip. Four T- way keys or ribs 32 are attached to the inner wall of the bowl I and are spaced to be received by the slots in the slips which when mounted on the keys may be slid from lower retracted or open position (Figs. 4 and 7) to an upper position (dotted lines in Fig. 4) toward the top of the bowl where they converge and close to form a conical frustrum having the cylindrical conduit or closure therethrough mentioned above.

Within one of the recesses of each slip is a curved finger 33 pivoted at 34 on the bottom wall thereof which forms the base of the slip. The finger 33 of each slip extends through a lateral slot 35 formed in the wall of each slip and through a like slot 36 into the recess or chamber 30 in the adjacent slip as shown in Fig. 7. It will be apparent that when the slips are slid upward on the keys 32 that the fingers 33 ride through the slots 36 further into the recess 30 of the adjacent slip and that the slips must move in unison to their converged or closed position toward the top of the bowl I even though pressure were applied only at the bottom of one of the slips.

A rubber member 37 (Figs. 4 and 6) is attached by means of stub bolts to the bottom of each slip and forms practically a continuation of the conical segments. The edges of the rubber members, however, extend slightly beyond the curved surface 21 (Fig. 5) of each slip so that when the slips are assembled the circular opening formed by the rubber members is about one-sixteenth inch less in diameter than the circular opening formed by the cooperating curved surfaces 2'! of the slips. The opening through the slips when closed is about one-sixteenth inch greater in diameter than the outside diameter of the drill pipe.

The rubber members are provided at all edges with the feathered edges indicated at 38 in Fig. 4. I have found it diflicult, if not impossible, to effect perfect sealing against high pressure without the use of such feathered edges. In addition these edges serve to deflect fluid pressure arising from the well against the bottom of the slips and cause their immediate raising to closed posiion.

The upper and lower bowls and 3 of the blowout preventer are provided with flanges 39 through which bolts pass for securing the members together. A sealing ring 40 (Fig. 4) having tapered walls is cast integral with the steel casing member I. A cooperating groove is accurately milled in the lower member 3.

The lower bowl of the blow-out preventer has cast integral therewith a depending portion 4| surrounding the tubular member l9. Webs 42 having openings 43 connect the parts just mentioned and serve as means for anchoring the blowout preventer with turnbuckles or with other suitable devices.

Pistons 43' disposed at the angle of the walls of casing and conical surface of the segments are mounted beneath each slip in cylinders formed in the depending portion 4|. The cylinders all connect with a manifold 5| formed by milling a circular groove around the bottom of depending portion 4| and welding a ring over the groove. The water inlet to the manifold is through an opening 44 formed in depending portion 4| above the manifold 5|. The horizontal opening 44 connects with a hole 50 drilled vertically through the top wall of the groove forming the manifold.

The opening 44 is connected to the water supply line 45 (Fig. 1). When it is desired to move the slips to closed position in anticipation of dangerous well pressure or for other reasons, the

' valve 46 is opened, the valve 41 being at that time closed. When the slips are lowered the water displaced by the pistons is forced out through the opening 44 and drains through pipe 45 and through opened valve 41, the valve 48 being closed.

It will be apparent, from the foregoing description, to those skilled in the art that the arrangement of parts described above presents several important advantages over the devices previously designed for the same purpose. Due to the fact that the drill pipe fits snugly but in non-gripping relation within the cylindrical closure formed when the slips are in operative position, and due to the fact that the feathered edges of the rubber members are compressed not only around the drill pipe but against the inner walls of the bowl I beneath the keys 32, the escape of fluid under pressure is effectively prevented from passing past the slips. In the event of a blow-out the only force tending to contact the rubber members with the drill pipe is that deflected by the feathered edges. Since but a relatively narrow ring formed by the resilient members contacts with the drill pipe the frictional resistance against the rotating pipe is small. Then also, since there is a space above the narrow resilient ring between the pipe and the closed slips, water can be run infrom the top which with mud forced up below the slips will lubricate the pipe so as to reduce to a minimum whatever wear that might take place.

. The mechanism described herein provides means, which may be the inter-connecting finger construction previously described or the simultaneously operated pistons, preferably both, for insuring the movement of the slips in absolute unison from their lowered to upper positions. If the fingers are not used the present invention, nevertheless, provides manual means for causing exact simultaneous upward movement of the slips for the reason that the manifold is always full of water by virtue of the previously described arrangement of conduits 44 and 50, and hence liquid pressure is instantly and simultaneously transmitted to the bottom of the pistons. This uniformity of operation cannot be obtained if the water is permitted to drain from the manifold and is likewise exceedingly difficult to obtain when gas pressure is used as the actuating means. I have found that the T-way slot and groove connection makes possible an easy and rapid sliding movement of the conical slips in the present device which I have not men able to obtain by means of dove tail keys and other forms of sliding connections. The slips of the present invention will not freeze or bind as devices of the present nature usually have a tendency to do. I have found the integral tapered steel sealing ring far superior to the usual use of packing material for the reason that the enormous weight of the bowl about 2200 pounds, often causes mutilation of the packing with consequent leakage- The separate holes for the exit and introduction of mud in the lower member of the blow-out preventer have also been found highly advantageous and result in a far more economical and simple installation than heretofore used in conjunction with drill pipes for preventing blow-outs. By means of the present construction the necessary pressure is easily and quickly built up to prevent the well from blowing in.

The most important advantage of my invention, however, is its capability of permitting continued rotation of the drill pipe after the slips have been raised into sealing position either automatically by pressure from the well or manually by the pistons. This advantage is highly important for the reason that the drill will freeze and bind in a comparatively short time after rotation ceases. The advantage of the present construction, which provides slips which do not grip and hold the drill pipe butwhich prevent fluid under pressure from escaping past the slips, will be readily apparent to those skilled in the art.

I claim: l

1. In a blow-out preventer comprising a casing, a plurality of slips within said casing movable relatively thereto from a lower retracted position toan upper closed position and cooperating to form an opening for the passage of a. drill pipe, said slips when moved to their upper closed position forming an elongated cylindrical closure for surrounding a drill pipe in non-gripping relation but providing slight but suiilcient clearance for continued rotation of the drill pipe, and. members carried by the slips cooperating when the slips are in closed position to form a relatively narrow ring of less diameter than the opening through said slips. said members being adapted to seal at the end of the closed slips the annular opening between the drill pipe and the surrounding walls of the closed slips.

2. In a blow-out preventer a casing having converging walls and provided with an opening at its smaller end for the reception of a drill pipe, a plurality of segmental slips slidable'relatively to said casing from a lower retracted position towards the smaller end of the casing to an upper converged closed position, means associated with said slips and casing for guiding said slips from one of said positions to the other, said slips when in said upper closed position forming a cylindrical closure adapted to completely surround in non-gripping relation a drill pipe passing therethrough and to provide suflicient clearance for continued rotation of the drill pipe, said slips being provided at their ends with resilient members having feathered edges which serve as means for deflecting fluid pressure for application against the body of the resilient members for raising the slips, the inner feathered edges of said members when the slips are in closed position forming an opening slightly smaller than but substantially concentric with the opening formed flverging walls and provided with an opening at its smaller end for the reception of a drill pipe, a plurality of segmental slips arranged for move ment relatively to said casing from a lower retracted position towards the smaller end of the casing to an upper converged closed position, a T- way connection between each slip and casing for guiding the slips from one of said positions to the other, said connection when the slips are in upper closed position terminating at a point not lower thanthe bottom of each slip, said slips when in said upperclosed position forming a cylindrical closure adapted to completely surrounda drill pipe passing therethrough, said slips being provided at their ends with resilient members having feathered edges which serve as means for deflecting fluid pressure for application against the body of the resilient members for raising the slips, and which when the slips are in closed position form an opening slightly smaller than but substantially concentric with the opening formed by the slips, and which extend beyond the lower faces of the slips beneath said T-way connection for preventing the escape of fluid under pressure between the slips and easing wall.

4. In a blow-out preventer a casing having converging walls and provided with an opening at its smaller end for the reception of a drill pipe, a

plurality of segmental slips movable relatively to said casing from a lower retracted position towards the smaller end of the casing to an upper converged closed position, and means for causing said slips to move in unison comprising pivoted fingers extending from one side of each slip into an opening in the side of the adjacent slip.-

5. In a blow-out preventer a casing consisting of an upper bowl having converging walls and provided with an opening at its smaller and for the reception of a drill pipe, a lower bowl, a plurality of segmental slips movable relatively in said upper bowl from a lower retracted position towards the smaller end of the bowl to an upper converged closed position, and'means for causing said slips to move in unison from said lower retracted position to said upper converged closed position, said means comprising pistons positioned beneath the slips, a common liquid manifold formed in the body of said lower bowl as a unitary part thereof, said manifold having passages therefrom leading to each of said pistons, said manifold having its inlet opening above its top wall to prevent drainage of liquid through said opening beyond that required for retraction of said pistons thereby maintaining said manifold full of liquid for instant and simultaneous operation of said pistons upon application of liquid pressure through said inlet opening.

6. The combination set forth in claim 5 in which said pistons are disposed at an angle substantially that of the casing walls.

, 7. In a blow-out preventer provided with an opening for the passage of a drill pipe therethrough, a plurality of slips movable from retracted to closed-position, said slips cooperating when in closed position to form a cylindrical conduit adapted to surround and provide slight but sufficient clearance for continued rotation of a drill pipe, and sealing means comprising resilient members carried by said slips, said resilient members having feathered edges which cooperate to form an opening of smaller diameter than said conduit 'for preventing the escape of fluid under pressure between the walls of the com duit and a drill pipe passingtherethrough.

ARTHUR L. RODGERS. 

